Let's begin with a dramatic day in the trial of the michigan valedictorian accused of murdering his mom. For the first time, the video seen of the defendant being interviewed by police. John muller has the details. Reporter: For the first time in his first-degree murder trial, jurors in the community that continues to stand behind him, heard from jeffrey pyne. Could you do anything at all to hurt your mom? No. Reporter: Pyne, a former high school valedictorian in 2008, stands accused of beating his mother, ruth, to death in the family garage. Prosecutors say he had a motive and opportunity. She got home from grocery shopping. And I helped her bring the groceries in. Reporter: Sitting in court wednesday, the 22-year-old showed little emotion. A stark contrast from the man jurors watched in this police interrogation video, shot hours after the murder. I'm having a hard enough time. Reporter: In the tape, police can be seen checking pyne's body for signs of a struggle. Can you take the bandages off your hands? Reporter: Officers also photographed injuries on his hand, blisters pyne said he got lifting wooden pallets at his job. She's a really nice lady. Reporter: Prosecutors suggest that was a lie. That ruth pyne had a history of mental illness and was often violent towards her children. In 2010, she was arrested and held in jail after attacking jeffrey. She just went mad, I guess. She wasn't depressed anymore. She just got crazy. Reporter: But the day of her death, jeffrey pyne told investigators things had been getting better. No type of fight or argument? We didn't argue today. Reporter: This morning, jeffrey pyne maintains his innocence. And while jurors may have heard his story on this grainy tape, it's still not clear if he'll take the stand to tell them in person. For "good morning america," john muller, abc news, new york.

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Valedictorian Matricide Trial: Jeffrey Pyne Interrogation Tape

Dan Abrams discusses the trial of Jeffrey Pyne, who is accused of killing his mother.